Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the one that is different.

322 : 18

322 : 18 - - ist number is the square of second number

as we know 18² = 324  but in this 322 is given thats why it is is odd

289 : 17 - ist number is the square of second number

225 : 15 - - ist number is the square of second number

484 : 22 - - ist number is the square of second number